Cryptography may be used to limit access to data. For example, sensitive data in computers or networks may be encrypted to block access by unauthorized users. Cryptography may be utilized to securely store information or to securely share information.
Different types of cryptography are in use today. Examples include symmetric cryptography and asymmetric cryptography. In symmetric cryptography, encryption and decryption are performed with the same “key.” Symmetric cryptography is sometimes also referred to as secret key cryptography, because the key cannot be disclosed for the data to remain secure. Triple-DES cryptography is an example of symmetric cryptography.
Asymmetric cryptography uses two keys: an encryption key, and a decryption key, where the encryption key is derived from the decryption key using a one-way function. In asymmetric cryptography, the encryption key (also referred to as the public key) can be disclosed since it can only encrypt and not decrypt data. The decryption key (also referred to as the private key) cannot be disclosed for the data to remain secure. Examples of asymmetric cryptography include Rivest-Shamir-Adleman (RSA) and elliptic curve cryptography.